The present disclosure is related to unmanned aerial vehicles. More particularly, the present disclosure is related to propulsion and control systems for unmanned aerial vehicles.
Propulsion units on traditional Unmanned Aerial Vehicles (UAVs) have limited maneuverability. In a typical four motor-rotor assembly, such as a quadcopter, the only controllable output is the thrust level, with all thrust directed in a downward direction, and the control of roll, pitch, yaw, and altitude achieved by adjusting the thrust level on specific propulsion units. The lack of thrust direction controllability confines the UAV to four degrees of freedom, as lateral translation is coupled with roll, and forward translation is coupled with pitch, and therefore the maneuverability and orientation of the central unit (“CU”) of a UAV is restricted. This restriction means the body of a traditional UAV is unable to tilt without creating an accompanying drift motion of the entire UAV. The inability to change thrust direction also makes flying upside down difficult and unstable.
Limited thrust direction is also a detriment in circumstances requiring a high degree of maneuverability or a stable platform for payloads. Limited thrust direction also restricts a payload's possible field of view. For example, photography payloads mounted under the fuselage of a traditional UAV have a limited view coverage because they are unable to look above their own horizon. The view coverage cannot be entirely spherical without a separate camera system, since a camera mounted under a fuselage is unable to see through the vehicle.
The speed and orientation of a UAV are also affected when altering the orientation of a traditional UAV's body, as they are coupled with sideways acceleration. This can limit a UAV's accessibility in enclosed environments, and its ability to interact with objects. Engine failure on a traditional UAV can disrupt the flight system and cause loss of control due to insufficient thrust or unbalanced torque. The likelihood of engine failure is even greater in environments with dusty air, high temperatures, flying birds, or environments with complex passages.